Inflammatory skin disorders are common diseases of the skin that take many forms, including psoriasis, atopic dermatitis, contact dermatitis, xerotic eczema, seborrheic dermatitis, discoid eczema, venous eczema, acne, rosacea, poison ivy, hives, and occupational dermatitis. Inflammatory skin disorders present with several symptoms, including desquamation, erythema, pruritus, and inflammation.
For example, atopic dermatitis (AD) is a disease characterized by dry, cracked, itchy, and inflamed skin, often presenting on greater than 10% of the body surface area. It accounts for 10-20% of all visits to a dermatologist and affects approximately 3% of the US population, most of whom are children. The condition is characterized by intense pruritus (itch) and a course marked by exacerbations and remissions. Higher transepidermal water loss (TEWL) has also been noted in dry skin atopic patients; TEWL is indicative of a disturbed barrier function, and it has been correlated to pruritus intensity in patients. Furthermore, the compromised skin barrier allows excessive water loss through the epidermal layer of the skin and the potential penetration of allergens.
A doctor has three main goals in designing a treatment regime for a patient suffering from an inflammatory skin disorder, such as AD: healing the skin and keeping it healthy; preventing flare ups; and treating symptoms when they do occur. Proper skin care and moisturizing ointments are the mainstays of topical treatment. Moisturizers which improve barrier function have been reported which reduce the prevalence of AD, and can reduce the associated symptoms.
In addition to moisturizers, a variety of medications may be prescribed to help manage the condition. Topical drug treatments for inflammatory skin disorders include steroids, calcineurin inhibitors, retinoids, vitamin D analogues, tars, anthralin, and keratolytics. However, the number of active ingredients is limited, and the range of dosage forms for these active agents is narrow.
There exists a need for stable, non-irritating topical formulations for the treatment of inflammatory skin disorders.